Linux kernel 3.4 has been released. New features include several Btrfs updates: support of metadata blocks bigger than 4KB, much improved metadata performance, better error handling and better recovery tools; there is also a new X32 ABI which allows to run programs in 64 bit mode with 32 bit pointers; several updates to the GPU drivers: early modesetting of Nvidia Geforce 600 'Kepler', support of AMD RadeonHD 7xxx and AMD Trinity APU series, and support of Intel Medfield graphics; support of x86 cpu driver autoprobing, two new device-mapper targets, several perf improvements such as GTK2 report GUI and a new 'Yama' security module. Here's the full list of changes.

I've been using XFS for years without a glitch. Fast, scalable, simply fantastic.

I did some testing with XFS a few months ago. An IO-bound process took over 5 days (!!) on ext3, 14 hours on XFS). In my testing, ext4 was a little faster than XFS, but it still takes *way* to long to fsck.ext4 a 1TB file system filled with tiny files. Fsck.xfs is always under 2 seconds.